Apparatus and method for rotary three-dimensional printing

ABSTRACT

An apparatus and method for fabricating a three-dimensional object. The apparatus includes a build rod for receiving successive layers of a build material therein. The apparatus also includes a drive mechanism to rotate the build rod and a print head disposed above the build rod. The print head is configured for dispensing a material onto the build rod to form a three-dimensional object.

FIELD OF THE INVENTION

The present invention is directed to an apparatus and method whichproduces objects using a rotary motion. In particular, it would bebeneficial to produce an object or part using a solid rod held in arotary chuck, thereby eliminating the need for a build plate and thebonding and release process associated therewith.

BACKGROUND OF THE INVENTION

It is common in plastic parts manufacturing to produce large batch sizesand serial parts by injection molding or extrusion. The advantage ofplastic injection molding is, in particular, owing to the highlyaccurate production of complex part geometries, whereby thefunctionality of the injection molding process optimally satisfies therequirements for the cost-effective and economical production of plasticparts.

However, the need for individual units and small batch sizes of plasticparts, with or without the requirement of being supplied within a shorttime frame and with properties similar to those of injection moldingparts, is continuing to grow. Manufacturing processes exist for theproduction of such parts which are widely known under the term“prototyping.” The production of such parts is generally based on thegeneration of the geometry from 3D data. These geometries are producedin a variety of forms by using the corresponding material, such asmeltable layers of powder by heat input, e.g. with lasers, by generativesystems such as printing processes, in various combinations of powderparts and using the “melt strand” process.

Various three-dimensional printing devices are currently available toproduce parts from such 3D data. Three-dimensional (3D) printing refersto processes that create 3D objects based on digital 3D object modelsand a materials dispenser. In 3D printing, a dispenser moves in at least2-dimensions and dispenses material in accordance to a determined printpattern. To a build a 3D object, a platform that holds the object beingprinted is adjusted such that the dispenser is able to apply many layersof material. In other words, a 3D object may be printed by printing manylayers of material, one layer at a time. If the dispenser moves in3-dimensions, movement of the platform is not needed. 3D printingfeatures such as speed, accuracy, color options and cost vary fordifferent dispensing mechanisms and materials.

One such device or apparatus is shown in EP 1 886 793 A1, which shows aplasticizing unit common to the injection molding technique coupled to amaterial reservoir that can be placed under pressure for the liquidphase of a material. For the production of an object on a slide in aconstruction space, this material is being discharged via a dischargeorifice in the shape of drops whereby, owing to the adhesive forces ofthe material, high pressure and generally high temperatures must also beapplied. The apparatus inlcudes means for the object carrier to move inthe x, y and z directions relative to the discharge unit.

Other devices and methods directed to polymer materials which areprinted based on the principles of ink jet printing are disclosed invarious patents, such as U.S. Pat. Nos. 6,850,334 B1 and 6,658,314 B1.In addition many patent and patent applications have published whichrelate to the design of the associated print heads and the eliminationof problems arising in the process (e.g. U.S. Pat. No. 6,259,962 B1, WO00/52624 A1, WO 00/76772 A1, WO 01/26023 A1, WO 01/53105 A2, WO2004/044816 A1, WO 2004/050323 A1, WO 2004/096514 A2, WO 2004/096527 A2,WO 2005/053928 A2, EP 1 637 307 A2 or DE 199 31 112 A1).

However, known system and methods of three-dimensional printing all usea stage or a platform on which the part or object is built. Once built,the stage or platform is removed. These systems are typically Cartesiansystems (i.e. XYZ based).

It would be beneficial to provide a system and method which producesobjects using a rotary motion which replaces the Y motion of theCartesian system. In particular, it would be beneficial to produce anobject or part using a solid rod held in a rotary chuck, therebyeliminating the need for a build plate and the bonding and releaseprocess associated therewith.

SUMMARY OF THE INVENTION

The invention is directed to an apparatus and method which producesobjects using a rotary motion. The apparatus and method allow forobjects which are, but not limited to, round, circular, arcuate orcylindrical in shape to be made with better resolution than can beaccomplished with a convention build plate and print head which move inthe X-Y-Z directions. The apparatus and method also allow customthreading, keying and other such details to be fabricated on suchobjects.

The invention is directed to an apparatus and method in which the buildrod is made of the same material which is used to fabricate the object,allowing the build rod to become part of the final object which does notneed to be removed.

An embodiment is directed to an apparatus for fabricating athree-dimensional object. The apparatus includes a build rod forreceiving successive layers of a build material therein. The apparatusalso includes a drive mechanism to rotate the build rod and a print headdisposed above the build rod. The print head is configured fordispensing a stream of material onto the build rod to form athree-dimensional object. In another illustrative embodiment, materialmay be deposited onto the build rod to form a three-dimensional object

An embodiment is directed to an apparatus for fabricating athree-dimensional object. The apparatus includes a build rod forreceiving successive layers of a build material therein. A drivemechanism is provided to rotate the build rod. A print head is disposedabove the build rod. A second drive mechanism is provided to move theprint head relative to the build rod. The print head is configured fordispensing a material onto the build rod to form a three-dimensionalobject.

An embodiment is directed to a method of producing a three-dimensionalobject, the method comprising of deposing material from a print headonto a build rod and rotating the build rod to create thethree-dimensional object.

Other features and advantages of the present invention will be apparentfrom the following more detailed description of the preferredembodiment, taken in conjunction with the accompanying drawings whichillustrate, by way of example, the principles of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a front perspective schematic view of an illustrative threedimensional printing apparatus according to the present invention.

FIG. 2 is a bottom perspective schematic view of the printing apparatusof FIG. 1.

FIG. 3 is a front schematic view of an illustrative build materialdelivery system for use with the printing apparatus of FIG. 1.

FIG. 4 is a front schematic view of the printing apparatus of FIG. 4with material deposited on the build rod to form an object.

FIG. 5 is a front schematic view of the printing apparatus of FIG. 4with the printing of the object complete and a portion of the buildingrod severed by the cutting blade.

DETAILED DESCRIPTION OF THE INVENTION

The description of illustrative embodiments according to principles ofthe present invention is intended to be read in connection with theaccompanying drawings, which are to be considered part of the entirewritten description. In the description of embodiments of the inventiondisclosed herein, any reference to direction or orientation is merelyintended for convenience of description and is not intended in any wayto limit the scope of the present invention. Relative terms such as“lower,” “upper,” “horizontal,” “vertical,” “above,” “below,” “up,”“down,” “top” and “bottom” as well as derivative thereof (e.g.,“horizontally,” “downwardly,” “upwardly,” etc.) should be construed torefer to the orientation as then described or as shown in the drawingunder discussion. These relative terms are for convenience ofdescription only and do not require that the apparatus be constructed oroperated in a particular orientation unless explicitly indicated assuch. Terms such as “attached,” “affixed,” “connected,” “coupled,”“interconnected,” and similar refer to a relationship wherein structuresare secured or attached to one another either directly or indirectlythrough intervening structures, as well as both movable or rigidattachments or relationships, unless expressly described otherwise.Moreover, the features and benefits of the invention are illustrated byreference to the preferred embodiments. Accordingly, the inventionexpressly should not be limited to such preferred embodimentsillustrating some possible non-limiting combination of features that mayexist alone or in other combinations of features, the scope of theinvention being defined by the claims appended hereto.

FIGS. 1-5 illustrate an apparatus 10 for three-dimensional printing ofround or cylindrical parts. The apparatus 10 produces or fabricatesthree-dimensional objects by depositing layers of a build material on abuild rod that ultimately forms the three-dimensional round, arcuate orcylindrical object. The apparatus 10 includes a rotary build rod 12, astructural device 14 for holding the build rod 12, a build materialdispenser assembly or print head 16 and an assembly 18 for moving theprint head 16 in the X and Z directions (as shown in FIG. 1).

The build rod 12 is generally cylindrical in shape and forms a centershaft on which the build material is deposited by the print head 16. Thebuild rod 12 can be made from various materials which are capable ofreceiving the build material thereon. In various illustrativeembodiments, the build rod 12 may be made of the same material which isused to fabricate or create the object. In such application, theconcerns regarding the release process of the object from the build rod12 is eliminated as the build rod 12 becomes part of the final object,as will be more fully described.

The build rod 12 is maintained in position by a structural device 14. Inthe embodiment shown, the structural device is a rotary chuck with acollet 20 which can be tightened to engage the build rod 12, therebysecuring the build rod in proper position relative to the print head 16.The collet 20 of the structural device 14 may also be loosened to allowthe building rod 12 to move in a direction parallel to the longitudinalaxis of the structural device 14 and the build rod 12. Although a collet20 is shown and described, other devices may be used to properly securethe build rod 12 in position.

In use, the build rod 12 is a shaft on which the build material isdeposited to create the desired object. In one illustrative embodiment,the build rod 12 may be positioned substantially parallel to themovement of the print head 16 in the X direction. In another embodiment,depending upon the object to be created, the build rod 12 may be angledwith respect to the movement of the print head 16 in the X direction.

The structural device 14 which holds the build rod 12 may be mounted ona drive mechanism 13 or rotary actuator that rotates the structuraldevice 14 and the build rod 12 about the longitudinal axis of thestructural device 14 and the build rod 12. The rotation may occur ineither a clockwise or counterclockwise direction. The rotary actuatorcould be hydraulically, pneumatically or electrically driven. The rotaryactuator may include gears and belts for driving the structural device14. In addition, the rotary actuator may include one or more encoders,or similar devices, that cooperate with a controller to monitor andadjust the speed and/or position of the structural device 14 and thebuild rod 12. The same encoders can also be used to control the firingof the print head 16, such that the print head 16 prints accurately andrepeatedly, regardless of variations in the rotational speed of thebuild rod 12.

The build rod 12 receives build material from the print head 16 that islocated adjacent to the build rod 12. In particular, the print head 16is mounted above the build rod 12 and dispenses build material onto thebuild rod 12 as the build rod 12 rotates. In one illustrativeembodiment, the print head 16 includes a volumetric adjuster formanually or automatically adjusting the amount of material beingdeposited. The print head 16 is supported on the assembly 18. In oneembodiment, the print head 16 may be supplied by a larger system locatedremotely from the apparatus 10 (FIG. 3). However, other print heads 16and systems may be used without departing from the scope of theinvention.

The assembly 18 includes a print head receiving member 30 which, in theillustrative embodiment shown, is a chuck with a collet 32 which can betightened to engage the print head 16, thereby securing the print head16 in proper position relative to the assembly 18. Although a collet 32is shown and described, other devices may be used to properly secure theprint head 16 in position.

Material is supplied the print head 16 by an apparatus 34, such as thatillustrated in FIG. 3. In the illustrative embodiment, the apparatus 34includes a hopper 36 and a plasticizer 38. However, other types ofapparatus can be used without departing from the scope of the invention.In general, apparatus 34 is configured to allow a wide range ofmaterials to be used to produce a three-dimensional object, such as, butnot limited to polymers, which may include, but are not limited to,filled polymers in the form of pellets or other ground forms. Thematerials can also include regrind. Any number of other materials can beused.

Assembly 18 includes mounting rods 40 on which a mounting member 42 ismoveably attached. The mounting member 42 includes the print headreceiving member 30 which holds the print head 16 in position. Themounting member 42 has openings 44 which extend therethrough and aredimensioned to receive the mounting rods 40 therein. A motor or drivemechanism 43 cooperates with the mounting member 42 to allow themounting member 42, the print head receiving member 30 and the printhead 16 to be moved in the X direction, which in the illustrativeembodiment shown is parallel to the longitudinal axis of the build rod12, as indicated by arrow 46 (FIG. 4), relative to the mounting rods 40.As the print head receiving member 30 and the print head 16 are mountedon the mounting member 42, the movement of the mounting member 42 causesthe print head receiving member 30 and the print head 16 to moveaccordingly.

The mounting member 42 could be hydraulically, pneumatically orelectrically driven and may include gears and belts for driving themounting member 42. In addition, the mounting member 42 may include oneor more encoders, or similar devices, that cooperate with a controllerto monitor and adjust the speed and/or position of the mounting member42. As previously stated, the same encoders can also be used to controlthe firing of the print head 16 and the movement of the build rod 12.

Proximate the ends of the mounting rods 40 are connection members 50.The connection members 50 have openings 52 for receipt of the mountingrods 40 therein. In the illustrative embodiment shown, the mounting rods40 are secured in the connection members 50, preventing the mountingrods 40 from moving in the direction of arrow 46 (FIG. 4). However,other configurations which allow the mounting rods 40 to move relativeto the connection members 50 can be used without departing from thescope of the invention.

The connection members 50 have slot or openings 54 which receive rails56 therein. The rails 56 are attached to a frame member 58. The rails 56extend in a direction which is essentially perpendicular to thedirection of the mounting rods 40. A motor or drive mechanism 51(FIG. 1) cooperates with the connection members 50 to allow theconnection members 50 to be moved in the Z direction, which in theillustrative embodiment shown is perpendicular to the longitudinal axisof the build rod 12 or away from the build rod 12, as indicated by arrow60 (FIG. 4). As the mounting rods 40, the mounting member 42, the printhead receiving member 30 and the print head 16 are mounted on theconnection members 50, the movement of the connection members 50 causesthe print head receiving member 30 and the print head 16 to moveaccordingly.

The connection members 50 could be hydraulically, pneumatically orelectrically driven and may include gears and belts for driving theconnection members 50. In addition, the connection members 50 mayinclude one or more encoders, or similar devices, that cooperate with acontroller to monitor and adjust the speed and/or position of themounting member 42. As previously stated, the same encoders can also beused to control the firing of the print head 16 and the movement of thebuild rod 12.

Alternatively, the structural device 14 may be movably connected to arail (not shown) or the like. In this embodiment, a motor or drivemechanism would cooperate with the structural device 14 to allow thestructural device 14 to be moved in the Z direction, which in theillustrative embodiment shown is perpendicular to the longitudinal axisof the build rod 12 or away from the print head 16, as indicated byarrow 60 (FIG. 4). As the build rod 12 is secured in the structuraldevice 14, the movement of the structural device 14 would cause thebuild rod 12 to move accordingly.

In operation, the build rod 12 is fed through the structural device 14to the appropriate length required for the desired object to be built.The build rod 12 is then secured in place to maintain the build rod 12is position relative to the structural device, as shown in FIGS. 1-3.

With the build rod properly positioned the printing process may beengaged. The print head 16 releases material which is received from theapparatus 34. The material released from the print head 16 is depositedonto the build rod 12. In the embodiment shown, the material is releasedin the form of a stream of material. As the build rod 12 is made frommaterial which is compatible with the build material thereon, the buildmaterial bonds to the build rod 12, as is known in the industry.

Once the material is released, the mounting member 42 and print head 16are moved in the direction of arrow 46 to deposit the material along thedesired length of the build rod 12. This process is repeated asrequired. Once material has been deposited along the desired length, thebuild rod is rotated to allow the next row to be deposited. Once theentire circumference of the build rod 12 has material deposited, asecond layer of material is deposited in the same manner. This iscontinued until the desired object has been formed, as shown in FIG. 4.

Alternatively, the build rod 12 may be rotated prior to the movement ofthe print head 16 in the direction of arrow 46. In this method, thematerial would be deposited along the entire circumference of the buildrod 12 prior to the print head 16 moving.

Once a layer is complete, the print head 16 is moved in the direction ofarrow 60 to provide sufficient space for the next successive layer.Alternatively, the build rod 12 may be moved in the direction of arrow60 to provide sufficient space for the next successive layer.

Once the object 80 is complete, a cutting mechanism or blade 70 is movedtoward the assembly 18 to sever the build rod 12 with the completedobject from the remainder of the build rod 12. The completed object isthan removed from the apparatus 10.

As previously stated, in application in which the build rod 12 is madeof the same material which is used to create the object, the build rod12 becomes part of the final object and does not need to be removed. Inaddition, if the construction of the final object does not require theremoval of the build rod 12, the build rod 12 does not need to beremoved. In such application, the concerns regarding the release processof the object from the build rod 12 is eliminated, as the build rod 12becomes part of the final object.

In another illustrative embodiment, the build rod 12 is a pre-molded orpre-built piece. In such instances, the material is deposited on thebuild rod 12 add features, such as, but not limited to keying orthreading.

The size and exact configuration of the apparatus 10 can vary to suit aparticular application. For example, the apparatus 10 could be sized tofit on a tabletop to produce relatively small three-dimensional objects,or the apparatus 10 could have a substantial footprint for producingrelatively large three-dimensional objects. In a particular embodiment,the size, including the diameter and/or the width of the build rod 12can vary to suit a particular application. Additionally, depending uponthe size of the build rod 12, the apparatus 10 may include multipleprint heads 16.

The apparatus and process described herein allows for objects which are,but not limited to, round, circular, arcuate or cylindrical in shape tobe made with better resolution than can be accomplished with aconvention build plate and print head which move in the X-Y-Zdirections. Additionally, the apparatus and process can be used tofabricate custom threading, keying and other such details on suchobjects.

While the invention has been described with reference to a preferredembodiment, it will be understood by those skilled in the art thatvarious changes may be made and equivalents may be substituted forelements thereof without departing from the spirit and scope of theinvention of the invention as defined in the accompanying claims. Inparticular, it will be clear to those skilled in the art that thepresent invention may be embodied in other specific forms, structures,arrangements, proportions, sizes, and with other elements, materials,and components, without departing from the spirit or essentialcharacteristics thereof. One skilled in the art will appreciate that theinvention may be used with many modifications of structure, arrangement,proportions, sizes, materials, and components and otherwise, used in thepractice of the invention, which are particularly adapted to specificenvironments and operative requirements without departing from theprinciples of the present invention. The presently disclosed embodimentsare therefore to be considered in all respects as illustrative and notrestrictive, the scope of the invention being defined by the appendedclaims, and not limited to the foregoing description or embodiments.

1. An apparatus for fabricating a three-dimensional object, theapparatus comprising: a build rod for receiving successive layers of abuild material therein; a drive mechanism to rotate the build rod; and aprint head disposed adjacent the build rod, wherein the print head isconfigured for dispensing a material onto the build rod to form athree-dimensional object.
 2. The apparatus as recited in claim 1,wherein the build rod is maintained in position by a rotary chuck. 3.The apparatus as recited in claim 1, wherein the build rod is made ofthe same material which is used to fabricate the three-dimensionalobject.
 4. The apparatus as recited in claim 1, wherein the print headis mounted to an assembly which allows the print head to move in adirection parallel to a longitudinal axis of the build rod.
 5. Theapparatus as recited in claim 1, wherein the print head is mounted to anassembly which allows the print head to move in a direction away fromthe build rod.
 6. The apparatus as recited in claim 1, wherein the buildrod is secured to a securing device which is movable in a direction awayfrom the print head.
 7. The apparatus as recited in claim 1, wherein acutting member is provided to sever the building rod after thethree-dimensional object has been fabricated.
 8. An apparatus forfabricating a three-dimensional object, the apparatus comprising: abuild rod for receiving successive layers of a build material therein; afirst drive mechanism to rotate the build rod; a print head disposedadjacent the build rod; and a second drive mechanism to move the printhead relative to the build rod; wherein the print head is configured fordispensing a material onto the build rod to form a three-dimensionalobject.
 9. The apparatus as recited in claim 1, wherein the build rod ismade of the same material which is used to fabricate thethree-dimensional object.
 10. The apparatus as recited in claim 1,wherein the print head is mounted to an assembly which allows the printhead to move in a direction parallel to a longitudinal axis of the buildrod.
 11. The apparatus as recited in claim 1, wherein the print head ismounted to an assembly which allows the print head to move in adirection away from the build rod.
 12. The apparatus as recited in claim1, wherein the build rod is secured to a securing device which ismovable in a direction away from the print head.
 13. The apparatus asrecited in claim 1, wherein a cutting member is provided to sever thebuilding rod after the three-dimensional object has been fabricated. 14.A method of producing a three-dimensional object, the method comprising:deposing material from a print head onto a build rod; and rotating thebuild rod to create the three-dimensional object.
 15. The method asrecited in claim 1, wherein the build rod is maintained in position andis rotated by a rotary chuck.
 16. The method as recited in claim 1,wherein the build rod is made of the same material which is used tofabricate the three-dimensional object.
 17. The method as recited inclaim 1, further comprising moving the print head in a directionparallel to a longitudinal axis of the build rod.
 18. The method asrecited in claim 1, further comprising moving the print head in adirection away from the build rod.
 19. The method as recited in claim 1,further comprising moving the build rod in a direction away from theprint head.
 20. The method as recited in claim 1, further comprisingsevering the building rod after the three-dimensional object has beenfabricated.